Tinting liquid and method of applying the same



UNITED. STATES PATENT [OFFICE f WILLIAM WHITEHEAD, OFOUMDERLAND,MARYLAND, ASSIGNOR TO COB- POB A TIO N OF AMERICA, A CORPORATION OFDELAWARE TTNTING LIQUID AND METHOD OF APPLYING THE SAME 7 Ho Drawing.

This invention relates to a tinting fluid for the purpose ofidentification of the same.

A further object of my invention is to tint yarns in a more distinctivemanner than has heretofore been possible, and at the same time toproduce tintings that may be scoured off more readily and rapidly.

A further object of my invention is to provide a tinting fluid fortextile yarns that acts both as a fugitive dyeing agency and as alubricant for the yarns. Further objects of my invention will appearfrom the following detailed description.

It is a common practice in the textile art to color yarns with an easilyremovable dye for the purpose for identifying them as to denier, countor size, twist, number of filaments, etc. during textile operations.After a finished product is produced, the color is removed by washing orscouring. Ordinar ily aqueous solutions of acid dyes (sodium salts ofsulphonic acids) are used for this purpose. The fugitive dyes areusually applied either by causing the yarn to pass across a wick or padthat dips into, or a roller that rotates in, an aqueous solution of thefugitive dye. Or else, the yarn is hanked and immersed in an aqueousbath of the dye. However, all of these methods have serious drawbacks.In the case where wicks or pads are used, these have a disadvantage ofshort life of but a few hours, because of the ready evaporation of thewater and the depositing of the undissolved dyestufi' thereon. Thiscauses irregular application of the dye and necessitates frequentchanging of the pads or wicks. Where rollers are used, it is exceedinglydifficult to supply the small amounts of tinting fluid required for thefiner types of yarns. The dyeing or hanking process involves the addedexpense of hanking and swift Winding and the waste produced thereby.

By the process of my invention all of these objections are obviated. Inaccordance with my invention, I prepare a tinting fluid whichApplication filed March 17, 1928. Serial No. 262,597.

contains as solvent for the fugitive dye, a

boiling polyhydric alcohol or a high boillng ether of such alcohol. Thetinting fluid may contain some water, but such' water is not absolutelynecessary.

Of the high boiling polyhydric alcohols that may be used in the tintingfluid, the fol-' lowing may be mentioned: glycerol (boiling point 290C.) ethylene glycol (boiling point 197 .5 0.); diethylene glycol(boiling point 250 C.) propylene glycol, etc. Of the ethers ofpolyhydric alcohols, the monoethers such asthe monoethyl ether ofethylene glycol (boiling point 135.5 G.) or the monoethyl ether ofdiethylene glycol (boiling point 187.5 0.), and the diethers, such asthe diethyl ether of diethylene glycol, may be mentioned. Obviouslyinstead of using only one of the above polyhydric alcohols or their;

ethers, a mixture of two or more of these may be used. In general asolvent whose boiling point is above 100 C. should be used.

While glycerol may be used in the fugitive tinting liquid, the glycolsor their ethers are preferred, since glycerol has the objection.- ableproperty of leaving sticky deposits on the apparatus, with which thetreated yarn comes in contact, such as cap-edges, fliers, travellers,etc, whereas the glycols or their ethers do not behave in this manner.

Since many of the polyhydric alcohols and their ethers are hydroscopic,I prefer to add suflicient water to the fluid to bring the aqueousconcentration to at least that of the maximum amount of water thesealcohols or ethers tend to absorb from the atmosphere, in order toprevent change of volume, viscosity and concentration of the tiltingfluid. Thus lycerol absorbs water to the extent of 33% 0 its originalweight from the air, ethylene glycol absorbs 3 to 4% and diethyleneglycol 30% of water, and therefore when either of these liquids areused, I prefer to add water corresponding to the respective percentagesset forth.

The 'dyestuff that is used may be any suitable dye that is used forfugitive tinting. The amount of dyestuffs used willvary with the natureof the dyestuffs and the purpose for which it is used. For example 0.5%to 1.0%

of dye in the tinting fluid is suitable for the urpose of identifying.arn in the bobbrn iiank or other package w en the tinting fluld isapplied in amounts of 0.5 to 2.0% of the weight of the yarn beingtinted. For identifying individual ends in warping, weaving and similarprocesses, a concentration of about 4% or over of the dye in the tintingflu1d m: is required, when the tinting fluid is applied in amounts of0.5 to 2.0% of the yarn being treated. Obviously these proportions aregiven merely by way of example and are not limitative of the scope ofthis invention.

The tintin fluid is appliedby any of the usual metho s for applyingtinting fluids to yarns, but I prefer to apply the same by causing theyarn'that is being wound, spun, etc. to pass across a wick or pad thatis dipping in or otherwise contacting with, the tinting fluid, sincethis method is most economical and Involves the use of a very compacttinting fluid apparatus that may be applied to all textile machineswithout difliculty. Because of the high boiling point of the solventsused in the tintin fluid and because of the other properties 0 thesesolvents, th'e wicks or pads have a very'long life, running into severalhundred hours, since the rate of evaporation of the solvents at normaltemperature is prac tically nil, so that no dyestufl' is thrown out ofsolution, and thus the wicks or ads do not become clogged with soliddyestu The solvents used in the tinting fluids possess excellentlubrication properties because of their comparatively high viscosity andoiliness. Therefore, I have found that when the tinting fluids hereindescribed are applied to yarns, further lubrication with oils, etc. isunnecessary in such cases as for example, banking, back-winding,ring-twisting, etc. of yarns of rayon or silk. In this connection it ispointed out that the lubricating value of ethylene glycel and diethyleneglycol: is

greater than that of glycerol.

In using the abovedescribed solvents in the tinting fluid, it is foundthat for a given ,amount of dyestufi on the yarn more distinct coloreffects are obtained. Thus when acid blue (Schultz No. 5430) is appliedin aqueous solution, the color imparted .to the yarn is decidedlygrayish, whereas when the same dye is applied in solution in thesolvents herein described, the color imparted to the yarn is distinctlyblue. Moreover, I have found that the color is more readily and quicklyremoved by scouring the yarns that have been tinted by a tinting fluidmade in accordance with my invention, than from those which have beentinted by aqueous tinting fluids.

An important ap lication of my invention is the fugitive tinting ofartificial yarns or filaments during the process of their manufactureand prior to their beingwound. For instance, in the manufacture ofcellulose acetate yarn by the dry spinning process, a solutile solventssuch as acetone, is passed through theorifices of a spinneret in a mtieror dry spinning machine into a heated atmosphere, and the filaments thusformed are drawn and wound and/or twisted onto an appropriate bobbin'orcap spinning machine.

When my invention is used in connection with a dry spinning process, thetinting solution is applied to the filaments or yarns on the mtier orspinning machine. In one aplication of my invention, the tinting li u1dis applied by means of a wick, which is ipping in a trough containingthe tinting fluid,- to the filaments just after their exit from themt-ier casing, both the wick and the trough being mounted on the mtieror dry spinning machine.

Because of the elevated temperature prevailing within the mtier, the useof the high boiling solvents mentioned above in the tinting fluid isparticularly advantageous in reducing the amount of clogging of thewicks. Since glycerol tends to leave sticky deposits, the glycols ortheir ethers which do not behave in this manner are preferred. Thus bythe use of a tinting fluid containing diethylene glycol, I have found itpossible to tint cellulose (rayon) lax or composite yarns contain-.

ing mixtures of these.

It is to be understood that the foregoing tion of cellulose acetate inappropriate voladetails are given merely by way of illustration and thatmany variations may be made therein without departing'from the spirit ofthis invention.

Having described my invention, what I claim and desire to secure byLetters Patent 1s:

1. A tinting fluid for the identification of yarns comprising a solventmedium having a boiling point about 100 C. comprising a compound of theglycol class and adyestuflr' dissolved therein. I

2. A tinting fluid for the identification of yarns comprising a solventmedium having a boiling point above 100C. comprising a glycol and adyestufl dissolved therein.

' 3. A tinting fluid for the identification of yarns comprisingdiethylene glycol and a dyestufi dissolved therein.

5. A tinting fluid comprising a polyhydric alcohol, water in amount atleast equal to that which'said polyhydric alcohol tends to absorb fromthe atmosphere and a dyestufi.

6. A tinting fluid comprising a glycol, water in amount at least equalto that which said glycol tends to absorb from the atmosphere and adyestufi.

7 A tinting fluid comprising a compound of the glycol class and adyestufl' dissolved therein.

8. A tinting fluid comprising a glycol and from 0.5% to 5.0% of adyestufi dissolved therein. 1 i

' 9, Method of tinting yarns comprising applying thereto a fluidcontaining a dyestufi dissolved in a solvent medium having a boilingpoint above 100 C. and containing a compound of the glycol class.

10. Method of tinting yarns comprising applying thereto a fluidcontaining a dyestuff dissolvedin a solvent medium having a boilingpoint above 100 C. and containing a glycol.

11. Method of tinting yarns comprising applying thereto a fluidcontaining a glycol and a dyestufi.

12. Method of tinting yarns comprising applying thereto a fluidcontaining a diethylene glycol and a dyestufi.

13. Method of temporarily marking yarns comprising adding thereto afluid containing a polyhydric alcohol, water in amount substantiallyequal to that which said polyhydric alcohol tends to absorb from theatmosphere and 'a in "tive dyestufi, whereas the yarns aresimultaneously tinted and lubricated.

* 14. Method in accordance with claim 13 wherein the polyhydric alcoholis a glycol.

15, In the dry spinning of filaments or yarns containing organicderivatives of cellulose in a mtier, the step of applying a tintingfluid to the filaments or yarns at the mtier, said tinting fluidcontaining a fugitive dyestufi dissolved in a solvent medium having aboiling point above 100 C. and contgining a compound of the polyhydricalcohol c ass.

16. In the dry spinning of filaments-or yarns containing organicderivatives of cellulose in a mtier, the step of applying a tintingfluid to the filaments or yarns at the mtier casing, said tinting fluidcontaining a fugitive dyestufi dissolved in a solvent medium having aboiling point above 100 C.

and containing a polyhydric alcohol.

18. In the dry spinnin yarns containing organic erivatives of cellulosein a-mtier, the step of applying a tinting fluid to the filaments orsaid tinting fluid containing mtier casing, a fugitive dyestuff yarns atthe and diethylene glycol.

In testimony whereof, I have hereunto subscribed my name.

WILLIAM WHITEHEAD.

17. In the dry spinmng of filaments or I yarns containing organicderivatives of cellulose in a fntier, the step of applying a tintingfluid to the filaments or yarns at the mtier casing, said fugitivedyestufi and a glycol.

tinting fluid containing a of filaments or

